The present invention relates to an electric plug for mounting on a trailer, for example, a wagon or car for connection to an electric socket on, for example, an automobile, truck or tractor, and more specifically to the plug terminal mounting arrangement for an electric plug for a trailer.
FIGS. 1 and 2 show a plug terminal mounting arrangement for an electric plug for a trailer according to the prior art. This arrangement is comprised of a terminal holder base, a holding down plate, six terminals, six U-shaped locating plates, screws, a U-shaped metal plate, a metal coupling screw, and a metal connecting block. According to this arrangement, the holding down plate comprises a plurality of V-shaped locating blocks raised from the top side thereof around the border. The U-shaped locating plates are respectively mounted between each two adjacent V-shaped locating blocks to hold the terminals respectively. The terminals each have a screw hole at one end respectively fastened to the U-shaped locating plates by a respective screw, and a locating hole on the middle. The metal connecting block and the U-shaped metal plate are fastened to both sides of the terminal holder base by the metal coupling screw. The terminal holder base comprises six equiangularly spaced hooked portions respectively and partially projecting into respective terminal slots thereon. When the terminals are mounted in the terminal slots on the terminal holder base, the hooked portions are respectively hooked in the locating holes on the terminals to hold terminals in place. When a 7-line power cord is installed, one wire of the 7-line power cord is fastened to the metal connecting block by a tightening up screw, and the other wires of the 7-line power cord are respectively secured to the terminals by the U-shaped locating plates and the respective screws. One drawback of this plug terminal mounting arrangement is its complicated assembly procedure. When mounting the holding down plate on the terminal holder base, the angular position of the holding down plate must be accurately aligned. If the holding down plate is not accurately set into position, the terminals will be forced out of position. Another drawback of this plug terminal mounting arrangement is that the U-shaped locating plates tend to be forced to contact with one another, causing a short circuit. Furthermore, when fastening up the screws to fix the wires of the 7-line power cord to the terminals and the metal connecting block, the terminals may be forced to contact one another, causing a short circuit.
The present invention has been accomplished to provide a plug terminal mounting arrangement which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the plug terminal mounting arrangement comprises a terminal holder base holding six terminals in respective terminal slots thereon, a U-shaped metal plate and a metal connecting block fastened to front and rear side walls of the terminal holder base by a metal coupling screw, six U-shaped locating plates respectively coupled between each two adjacent V-shaped locating blocks at the rear side of the terminal holder to hold the terminals in place, and a 7-line power cord having 7 wires respectively connected to the metal connecting blocks and the terminals, wherein the V-shaped locating blocks are integral with the rear side wall of the terminal holder base, each V-shaped locating block having a partition board on the middle, the partition boards of the V-shaped locating blocks being respectively spaced between each two adjacent U-shaped locating plate to prevent the U-shaped locating plates from contacting one another. According to another aspect of the present invention, the terminal slots of the terminal holder base each have a rectangular cross section at one end extended to the front side wall of the terminal holder base, and a T-shaped cross section at an opposite end extended to the rear side wall of the terminal holder base, the T-shaped cross section of the terminal slots stopping the coupling portions of the terminals from passing through when the terminals are inserted through the rectangular cross sections into the terminal slots and be simultaneously pressed forwards by a press.